From what Mearls says in the
video it will actually be somewhat different from Star Wars d20.
If I'm interpreting correctly the main effect of wounds is to reduce your ability to sustain hit point (vitality) damage over the long term, but to me it doesn't sound like there is a separate pool of "wound points" or anything like that. I imagine they did something like that so a crazy crit will have some long-term consequences without turning things into rocket tag. Changing maximum hp to represent wounds hopefully means almost everything in the game besides the rules for getting a wound and healing them simply works without changes: You would still fall unconscious at 0 hp, etc.
I'm just guessing, but from the last sentence in the quote maybe they're doing something like reducing maximum hp by damage taken divided by 5 (round down).
I made a
post suggesting and analyzing a very similar-sounding system a couple years ago so I'm pretty interested to see what they came up with.